France-based Aircall is targeting companies that require a customer service operation. But rather than a traditional approach of creating a dedicated customer support office — something that takes time, is a significant cost and not particularly optimized — the service uses smartphones and Internet telephony trickery to make things easier and instant — not to mention cheaper.

Instead of a physical customer support office with phone operatives, Aircall customers can use the company’s app to run a virtual customer support team. Customer support agents just need the company’s app — available on web and launching for iOS this week — which routes calls through.

The service allows companies to manage their agents with some sophistication, too. For example, priorities can be set for teams — to ensure that one person takes calls first, or calls from specific locations, countries or even customers are handled by a certain person. So requests from high-priority customers, or in a specific language can be handled.

Similarly, if an agent has to call out they can choose their location (using a local number in one of 30 countries) to make an outbound call seem familiar to the customer who is receiving it. Number generation is instant, and there’s a simple, Slack-like interface to manage the internal team and other setting.

The consumer-facing parts of the service are designed with the same lightweight and simple approach. Rather than asking a customer to punch a number into their phone to reach a call center, Aircall uses a web-based virtual keypad that customers can embed on their website. That takes hassle and cost out of the equation.

Aircall works by routing calls over the Internet — using the kind of VoIP tech that powers Skype, messaging apps and more — but it also uses cellular. That means that you can take an inbound call over your laptop, tablet or smartphone — in the case of the latter, Aircall CEO Olivier Pailhès explained that regular calls are a safer bet for quality. Likewise, iOS prioritizes cellular over VoIP, so your business call will be dropped if your wife or significant other rings you up, for example, unless it is cellular.

The service is charged from $10 per user on its most basic plan, up to a more robust $40 per user tier. Outbound calls are metered based on each payment plan — up to four hours per user on the top tier — and there are integrations with Slack, Salesforce and other CRM tools based on each tier.

Pailhès said the team is just scratching the service for what the iOS app can do. He wants to expand the capacity of the system to cover enterprise customers and plans to introduce an app for Android, too. The company is registering 40 percent month-on-month growth, he claimed, and right now one-third of its 400 customers are U.S.-based, which explains why the company is putting a major focus on the U.S. market. As well as appearing at Disrupt, it is part of 500 Startups‘ current Silicon Valley-based accelerator program.

“We can expand from being a solution for working at the office. Now anyone can do all their professional calls from the app,” Pailhès said.

Aircall previously raised $800,000 across two seed rounds in Europe. Pailhès said the company is currently looking to raise $2 million from U.S.-based investors to grow its business in country. He wants to hire sales and marketing staff in the U.S., but the tech team will remain based in Paris, France.